1. Field of the Invention
This invention relates to a method and apparatus for forming sheaves of the type having an annular peripheral groove for receiving a wire line therein; more particularly, this invention relates to the method of forming a sheave of the type referred to above from a flat circular disc by rotating, heating and forming said groove in the periphery of said disc.
2. The Prior Art
Sheaves of the type having a groove for receiving a wire line or rope therein have been manufactured heretofore in a number of different ways. Normally, this type of sheave can be made by casting the sheave including the groove and rim, in which case the product has to be machine finished. Occasionally, a sheave of this type will be forged, such as in a closed die forging; again, the forged product will be generally subjected to a final machining. It has also been known that a complete sheave can be machined from a plate of steel. Sometimes the sheave can be fabricated in sections by forming the groove as a straight piece, rolling the same into a hoop, butt welding the hoop and then welding the hoop to a disc of steel and hub or to spokes and hub; this fabricated product will also have to be machine finished. Certain types of pulleys have been manufactured in the past by splitting the peripheral edge with a sharp rotary knife blade. The prior art does not show or suggest the hot roll forming of a sheave from a flat disc of metal.